Medical devices which are energized by laser generated radiant energy such as scalpels or angioplasty systems are known. Such devices use a laser source to generate focused monochromatic radiant energy. This radiant energy is then injected into a fiber optic cable for transmission to the treatment effecting instrument.
As higher power lasers have become available, it has become apparent that more efficient coupling systems are needed between the focused radiant energy laser beam and the fiber optic cable.
With high power lasers, the focused radiant energy beam can have an energy density which is great enough to damage, by softening, melting, or fusing, any materials which are not highly optically transmissive. In addition, it is well recognized that to inject and transmit radiant energy into an end of and along a fiber optic member, the energy must be injected within a predeterminable acceptance angle with respect to the axis of the cable. This angle defines an acceptance cone.
Light incident on the end of the cable at an angle which exceeds the acceptance angle will, in all likelihood, not be transmitted along the fiber but will be radiated from the periphery of the cable. Thus, light incident at an unacceptable angle is one source of lost radiant energy which can produce heat in a coupling system.
A second source of radiant energy which produces heat in a coupling system is spillover radiant energy which is not injected into the end of the fiber optic cable. This spillover energy component is due to the output of the laser beam not being perfectly focused to produce a spot size equal to or smaller than the diameter of the input end of the fiber optic cable. Additional sources of radiant energy which produce heat in a coupling system is that portion which enters the cladding of the fibers as well as energy transmitted in the space between fibers.
Hence, there is a need for coupling systems which are usable for coupling radiant energy to fiber optic cable while simultaneously providing for deflection and dissipation of radiant energy which exits the fiber optic cable in the vicinity of the connector system, and for deflection and dissipation of spillover radiant energy not injected into the fiber optic cable. Preferably, such a coupling system would not generate inordinate amounts of heat so as to be uncomfortable or dangerous to a user. In addition, such a coupling system would preferably be relatively small.